What reactions take place at the cathode and the anode when each of the following is electrolyzed? Assume standard conditions. (Use the lowest possible coefficients. Omit states-of-matter from your answer.)
I got the cathode for one and the anode for another, but I don't know if I should take into account possible hydrolization? This is what I have so far. (a) 1.0 M CdCl2 solutioncathode: Cd^2+ +2e^- --> Cdanode: Cl_2 -->2Cl^- +2e^-For this one the cathode was marked right and the anode was marked wrong.(b) 1.0 M AlBr3 solution
cathode: Al-->Al^3+ +3e^-
anode: 2Br^- -->Br_2 +2e^-
For this one the cathode was marked wrong while the anode was marked right
I'm not sure what I am supposed to do from here as I got part of the questions correct. I don't think I understand how to get the other halves of the questions. Thank you
What reactions take place at the cathode and the anode when each of the following is electrolyzed? Assume standard conditions. ?
2020-08-21 2:04 am
回答 (1)
2020-08-21 2:21 am
(a)
The dissociation of CdCl₂ gives Cd²⁺ and Cl⁻ ions, while the slight dissociation of water gives H⁺ and OH⁻ ions.
Cd²⁺ and H⁺ ions migrate to the cathode. At the cathode, Cd²⁺ ion is preferentially discharged because Cd²⁺ ion has a higher concentration than H⁺ ion.
Cd²⁺ + 2e⁻ → Cd
Cl⁻ and OH⁻ ions migrate to the anode. At the anode, Cl⁻ is preferentially discharged because Cl⁻ ion has a higher concentration than OH⁻ ion.
2Cl⁻ → Cl₂ + 2e⁻
====
(b)
The dissociation of AlBr₃ gives Al³⁺ and Br⁻ ions, while the slight dissociation of water gives H⁺ and OH⁻ ions.
Al³⁺ and H⁺ ions migrate to the cathode. At the cathode, H⁺ ion is preferentially discharged because it is hardly for Al³⁺ ion to be reduced.
2H⁺ + 2e⁻ → H₂
(Sometimes written as: 2H₂O → 2OH⁻ + H₂)
Br⁻ and OH⁻ ions migrate to the anode. At the anode, Br⁻ is preferentially discharged because Br⁻ ion has a higher concentration than OH⁻ ion.
2Br⁻ → Br₂ + 2e⁻
The dissociation of CdCl₂ gives Cd²⁺ and Cl⁻ ions, while the slight dissociation of water gives H⁺ and OH⁻ ions.
Cd²⁺ and H⁺ ions migrate to the cathode. At the cathode, Cd²⁺ ion is preferentially discharged because Cd²⁺ ion has a higher concentration than H⁺ ion.
Cd²⁺ + 2e⁻ → Cd
Cl⁻ and OH⁻ ions migrate to the anode. At the anode, Cl⁻ is preferentially discharged because Cl⁻ ion has a higher concentration than OH⁻ ion.
2Cl⁻ → Cl₂ + 2e⁻
====
(b)
The dissociation of AlBr₃ gives Al³⁺ and Br⁻ ions, while the slight dissociation of water gives H⁺ and OH⁻ ions.
Al³⁺ and H⁺ ions migrate to the cathode. At the cathode, H⁺ ion is preferentially discharged because it is hardly for Al³⁺ ion to be reduced.
2H⁺ + 2e⁻ → H₂
(Sometimes written as: 2H₂O → 2OH⁻ + H₂)
Br⁻ and OH⁻ ions migrate to the anode. At the anode, Br⁻ is preferentially discharged because Br⁻ ion has a higher concentration than OH⁻ ion.
2Br⁻ → Br₂ + 2e⁻
收錄日期: 2021-04-24 07:58:16
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